1. Field of the Invention
The present invention relates to a case, a strap and a timepiece combined with the case and the strap.
2. Description of the Prior Art
An explanation will be given of a conventional case, a conventional strap and a conventional timepiece in reference to the drawings. FIG. 3 is a sectional view in a state of a timepiece attaching a strap to a case. FIG. 4 is a sectional view of the case and the strap.
A conventional case 5 is provided with a strap attaching portion roof 52 for attaching a strap 6. The strap attaching portion roof 52 is provided with a strap attaching portion 51 constituting a space for bringing a portion of the strap 6 to a side of a caseback (hereinafter, referred to as ‘bottom side’). Further, the strap attaching portion 51 is opened with a spring rod pin hole 55 for inserting a spring rod 3.
Further, the conventional strap 6 is provided with a spring rod hole 65 for inserting the spring rod 3 in a width direction of the strap. A periphery of the spring rod hole 65 is provided with a strap inserting face 62 for inserting to the strap attaching portion 51. Further, the strap inserting portion 62 is provided with a stepped difference such that the strap 6 is prevented from rotating when the strap 6 is attached to the case 5. Further, the strap 6 is provided with a rotation stop tongue 67 which is brought into contact also with a case back 57 to thereby prevent rotation.
Further, the conventional timepiece is assembled with the strap 6 and the case 5 by inserting the spring rod 3 into the spring rod hole 65 of the strap 6 and inserting a front end of the spring rod 3 into the spring rod pin hole 55 of the case 5.
The conventional timepiece has a problem in that when the strap attaching portion has stress applied thereto for rotating the strap in a direction of a rear face thereof, a large gap is produced at a portion of coupling the case and the strap, or the strap is rotated.
Further, in order to prevent the rotation, there is a method of setting positions of a spring rod pin hole of a case and a spring rod hole of a strap and attaching the case and the strap by a spring rod 3 constituting a connecting member in a shaft-like shape penetrating the case and the strap such that the strap is pressed to attach to the case as much as possible by utilizing elasticity of the strap. However, the method has a problem in that repulsive force produced by pressing the strap to the case is always applied to the spring rod pin hole for holding the shaft-like connecting member of the case shown in FIG. 4 respectively in a horizontal direction f1 and a vertical direction f2 and therefore, the case is deformed by the repulsive force. When the repulsive force is strong, a crack can occur. When the shape of a surrounding of the spring rod pin hole 55 is deformed, the spring rod cannot be held and the strap is detached from the case.